Apparatus for applying abrasives to grinding-machines.



H.K.HITCHGOGK. APPARATUS FOR APPLYING. ABRASIVES T0 GRINDING MACHINES. 1,077,982.

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APPLICATION FILED MAY 17, 1912.

Patented Nov. 11,1913.

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INVENTOR KAZZZM ma /M I I I l LIA l H. K.-HITGHGOGK. APPARATUS FOR APPLYING ABEA'SIVBS TO GRINDING MACHINES.

APPLICATION FILED MAY 17-, 1912. 1,077,982.

Patented Nov. 11, 1913.

WITNESSES H. K. HITGHGOGK. APPARATUS FOR APPLYING ABRASIVBS T0 GRINDING MACHINES.

APPLICATION PILED'MAY 17, 1912. 1,077,982. Patented Nov. 11, 1913.

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W5 WM- H. K. HITGHGOGK. APPARATUS FOB APPLYING ABEASIVES T0 GRINDING MACHINES. APPLICATION FILED MAY 17, 1912.

1,077,982. P Patented Nov.11,1913.

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fiill'ifiifilyi K. HITCEECDCK, DE TARENTUM, PENNSYLVANIA.

APPLYING ABRASIVES TO GRINDING-MACHINES.

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so Grinviing-lvlschines. of .which following-is s specification.

lhis invention relates .to sppsi'etus for grading end applying .finelv divided inslEQP-liil mixed with Waiver, and especially for grading send or other .shisding material for use with grinding mushinw.

In the grinding and snioolhinmof' material requiring e line surface, sucn us plate glass, marble and grunisc, it is desii'able that after the abrasive has passed between the material t he ground encl the runners or .rubbinghed, the finer particles be separated from the courses ones and saved to be used in the finishing operation and that the course!" particles he regrsded and returned :to the gninding mechanism to assist in the roughing operation.

In my Palms-N 934. %1, @eptemher 21, 1909, is described and claimed process for grading fine material in suspension and in my Patent No. 934,612, September 21 1530 is illustrated and described certain apps.- mtus for grading materiel, conducting the same to grinding apparatus and then returning it for reuse. In my application filed July 31, 1911, Serial No. 6411.483, is described and claimed apparatus which is an -inuu'ovement upon that illustrated and clescribed in my Patent 334.1312 above, which improvements include, among; other feuturcs, the wilhdrswsl of the graded msh 1 1 tonal from diflerent heights in the grading vessel or cone, such Withdrawal going .on simultaneously Willi the supply of the ungraded material to such vessel and provision for u, continuous cycle of circulation the abrasive in suspension from the grading: vessel to ihe grinding; table. n clhucl-z again its and through gr presen'c up:

.21 monk upon The app: 934.612 sud my 641,483, aha e ides has n certs o lows she mono scribed in .Psienl No. pix-ruins oi my prior 3 Specification of Letters Patent.

Patented Nov. n, 1913.

lippliceticn filed Kiley 17, 1312. serial No. 697,863.

shove identified a centrifugal pump is employed for Withdrawing the sand and water irons the sum. and forcing it up into the grading vesse through its lower end, and

according to the method described an up- Willtl current of water is thus produced in ihe'grsding vessel or cone 01 effecting the grading operation. I

Thslsction of the sand and water is veryhans ion the centrifugal pump and quickly wears out. -One of the principal purposes of the present invention is to dispense with such pump so as to overcome the annoynnce clue to its rapid wear and to provide.

apparatus wherein the sand aud'water re turned from the grinding apparatus "is introduced into the grading vessel by g vity flow solely. As a consequence the u. ard

flow in the grading vessel isnob as pronounced as with the apparatus of the prior patent, but the materials are nevertheless graded.

In the accompanying (ll-swings Figure is a. plan view partly broken avv'sy of apparstus embodying the present invention; Fig. 2 is in part a side elevation and in part s, verticsl section on the line 11-11, Fig. 1; Fig. 3 is also in part an elevation and in purl: a verticalsection on the line IH-HL Fig. 1; Fig. 4 is a vertical section on the line l-VIV,Fig. 1; and Fig. 5 is a. vertical elevation, Fig. 6 a. similar view at right angles to Fig. 5, and Fig. 7 a top plan view of s modified arrangement of apparatus.

In the drawings 1 represents a grinding table of any suitable character, such as used for instance for grinding plate glass. Coopersiing with the table are a pair of'runno se 2. as is usual with this form of appui'utus.

3 is a perforated pipe or trough above the table for supplying the abrasive iheretol l is s gutlor surrounding the table, as is usual. (in one side this gutter communicules with a radial gutter 5, which has n cci'mocfion llmzugh El screen 01' strainer (3 with u. ci'unluil F" communicating with u.

swivels-(l iHPl pipe 8 for conducling the 1.3lX-.

ii are a pair of grading vessels.

table through spout 8 by gravity flow, and capable of being elevated so as to discharge to the grinding table also by gravity flow, such as through pipe or conduit 12 connected with the perforated pipe 3. In the premounted on the framework 17, said cables being connected to the vessels by any suitable means, such as the equalizing bars 18 and clevises 19. As a consequence, the vessels partly counterbalance each other so as to reduce the power necessary to change their relative positions. For the latter purpose each of the vessels is mounted on the upper end of a piston rod 20 of a suitable power cylinder 21, such as a hydraulic cylin der, located'vertically underneath each vessel and having connected thereto a suitable pipe 22 provided with control valve 24 for admitting water or other pressure medium to the cylinder and exhausting the same therefrom. l/Vhen the valves 24 are so set as to allow the pressure medium to escape from one of the cylinders 21 and to admit pressure medium to the other cylinder, the latter will be lifted, and as the vessels are connected by the cables, this allows the elevated vessel to settle and expel the pressure medium from the cylinder thereunder.

Figs. 5, 6 and 7 show a modified arrangement in which no positivepower mechanism is used for changing the relative positions of the grading vessels or cones, but instead the one is elevated by the superior weight of the other one. To this end each of the vessels is provided some distance below its top with an outlet pipe 25 having a valve 26 with controlling handle 27 by means of which the level of liquid in the vessel can be lowered so as to lighten the vessel'and' enable the elevated one (which is full) to overbalance it so that it will pull the lighter vessel to elevated position. In this case a pair of the cables 14 which connect the two vessels are wrapped around intermediate sheaves 28 'on a shaft 29 provided with a brake wheel 30 on which are a pair of reversely arranged brake bands 31 connected to arms 32 or a control lever 33. By means of this lever the friction brake can be released to permit the heavier elevated vessel to descend into the pit 11 and pull the lighter vessel to elevated position. The friction brake gives absolute control over this movement so as to prevent a, sudden drop. Said lever is locked in any; position by means of the raclzf'al.

Many other arrangements of apparatus will readily suggest themselves for changing the relative positions of the vessels, the

grinding table and from the grinding table to the lowered vessel purely by gravity flow, thereby dispensing with pumps or like means for elevating the liquid and abradant. The spout or pipe 8 for directing the water and sand into the vessels when lowered into the pit has its end bent at right angles to its body, as clearly shown in Figs. 2 and 3, and is rotatably mounted or swiveled so that it can be swung to diametrically opposite positions to discharge into one or the other of the vessels. In Fig. 2 the full line position of pipe 8 shows the same discharging into vessel 10 which is now in the pit. When this vessel is being elevated, in its upward movement it contacts with and rotates the spout 8, turning the bent end upwardly, and as the vessel 9 descends its top flange contacts with one of the lugs 8 on pipe 8 and turns the latter to the dotted line position, shown at S, Fig. 2, so that it can then discharge into the then lowermost vessel 9.

Each of the vessels is provided in its top with a transverse trough 36 sloping from the periphery to the center and communicating with opening 37 cent-rally of the vessel. The liquid and abradant is discharged by the spout 8 int-o this trough 36 and escapes through the central opening 37 into the vessel. This form of grading vessel differs from those shown in my prior patents and applications in that while provision is made for introducing a stream of liquid through the bottom of the vessel this liquid is preferably shut oif while receiv ing the abradantj .The material, grades itself somewhatac'ccrding to size owlng to the more rapid falling of the heavier particles down through the suspending liquid. In order to understandthoroughly the action of the form of vessel shown in the drawings the principle governing the action may be briefly stated as follows: A body falling freely in vacuum has a uniformly accelerated velocity with a fixed increment of acceleration due to gravity. This acceleration is the same for all bodies. If instead of falling in a vacuum, the body falls through a liquid, its fall is resisted in proportion to its projection or area in a horizontal plane and to the extent of its wetted -termedits critical velocity for that liquid.

newness surface. This resistance increases as the square of the velocity of fall. It will there-, "fore be readily seen that as the force of gravity remains constant while theresistance of the body falling through the liquid increases as the square of the velocity, that sooner or later this resistance will equal and {entirely absorb the acceleration due t6 gravity, after which time the body will fall with a constant velocity; which'may be The ,wetted area and the projection of bddies of similar onto; r increases as the square of any of t eir 'milar dimensions, while their weight increases as their densitIy and the cube of their similar dimensions. t is therefore evident that this constant or critical velocity while falling in the liquid increases as the particles grow larger, so that bodies having similar shapes and densities but of varying sizes falling through a vertical tank of infinite length filled with water begin to separate according to their size, the larger particles falling faster than the smaller ones, and the distance separazing them increasing with the time. In addi ion to this natural separation the heavier particles displace their own volume of water, thus creating an upward flow of water equal in volume to the downward movement of the particles, the volume of this uptlow increasmg from the lowest particles to the highest due to the added water displaced by the particles-above. This added velocity serves to still further retard the down-ward movement a of the particles higher up, so that if the quantity of solids added are sufficient and the finest particles small enough the latter will be carried up by this upward flow and washed out over the top of the tank.

If the tank is of inverted cone or pyramid sha e increasing in cross section upwardly, as tile coarser particles fall -they are crowded together by the downward converging walls so that their volume forms a gradually in creasing portion of the total liquid and gradually increases the upward velocity in the lower part, which magnifies the grading action. This action takes place in the grading vessels illustrated in the presentapplication, which are of inverted cone form and in which the mixture of sand and water is introduced from the top. The larger particles falling faster than the lighter ones on the principle above explained, displace the water at the bottom of the cone and cause an upward flow which is effective in separating the sand into grades according to size. As a consequence the material in the vessel receiving the inflow of material at its top is undergoing a preliminary grading, and by the time the vessel is'full, the material is separated into strata or zones of mod erately well defined sizes, the coarser material being in the lowermost strata and the material decreasing in size upwardly. The

bulk of the very fine material and scummy 'matter overflows through a spout 40 discharging into a conduit 41 in'the wall of the pit and leading to a sewer connection 42. Thelfiner sands are then allowed to settle .somewhatand the superfluous water in the top of the vessel is drawn ofi' through the discharge pipe 25, which discharges into a basin 43 communicating with the sew'er connection. These sewer connections are made on both sides of the pit so that each vessel can discharge in the same manner.

The operation just described is that which takes place when no water is admitted into the bottom of the vessel at the time it is receiving the inflow of sand and water, such as occursin case no-water supply pipe is connected to the lower end of the vessel or in case the same is closed. The preferred forin of apparatus, however, includes a water supply pipe 54 to the lower end of the gradmg vessel, as shown in the drawings, and

particularly is this the case when the clevertors illustrated in Figs. 1, 2, 3 and 4 are employed so-that this water may run con tinuously and thereby secure a more rapid operation and a more perfect grading in the vessel, and have the grading fully completed by the time the vessel is ready to elevate. At the point where pipes 54 connect to the lower end of the vessel, are preferably placed check valves 54 to keep the sand from backing into the pipes at when the water is shut off.

The vessels may beef any suitable shape or size, but preferably are of inverted cone shape having sides at sucli an angle as to produce a considerable velocity upward from the bottom to the top where a given mixture of solids are continuously introduced at the top. It is preferred to withdraw the several grades or strata from the vessel independently or separately, so that it will not be necessary to entirely exhaust any one grade before beginning to withdraw the next finer grade as described in my application Serial No. 641,483, above identified. To this end the discharge from the cone when in its elevated position is through a series of pipes opening-at different levels or heights in said 'cone, Any number of such pipes may be introduced, but as shown there are three pipes 45, 46 and 47 opening into the tank at dilierent-heights and all extending upwardly to substantially the same level and then passing through the side wall of the cone or vessel, Where they are provided with control valve mechanism indicated generally at l8, but not specifically shown or described, by means of which any one of said pipes may be opened to discharge the particular 'rade inthe strata at which the inner end oi that particular pipe opens. The form of valve mechanism for controlling these pipes is not discharge pipes of the other vessel or cone, 1

specifically illustrated herein, being the same as fully illustrated, described and claimed in my application, Serial No. 041,483. All of these pipes discharge into the spout or conduit 12.

In order to permit ,of the lowering of the vessels the spout 12 is movable so that its upper end can be swung out of the position underneath the outer ends ofthe dischar e pipes of one vessel and brought into a si ilar position underneath the outer ends of the as indicated in dotted lines in Fig. 1. To this end the conduit 12 is swiveled at 50 and its higher end is supported upon a way or guide 51 upon which it can be slid from the full line position to the dotted line position shown in Fig. 1.

The water connection 54 to the bottoms ofthe vessels not only grades the material as it flows into the vessel, but if closed when the material flows into the vessel it serves as a means of completing the grading operation after the vessel is lifted and also keeps the abradant in suspension in the liquid in the vessel while being withdrawn therefrom. The pipes 54- for the two vessels are connected by flexible pipes or hose 55 to a suitable three-way cock 55 in a supply pipe A two-way regulating cook 57 is provided at the lower end of the cone for connecting the cone with a discharge opening 58. The pipe 54 also extends upwardly at 59 and connects with the outer ends of the discharge pipes 45, 46 and 47 for the purpose of creating an inward flow therein for removingany stoppage and cleaning them out, all as described in my application, Serial No. 641,483, above identified, and not herein specifically .shown or described.

The overflow from the vessels when in elevated position escapes through the overflow spouts 40 into tanks or basins 61 supported at an elevation and having pipes 62 connected thereto and leading to the gutter 4 and discharging thereinto at 63. Other pipes (5st also open into the tanks or basins 61 and project upwardly therein, to take the overflow from said tanks or basins, and particularly the mud and fine abradant or scum, said pipes 64 having a connection at 65 to sewers 66 which also take the overflow from the cross gutter 5.

The sewers G6 and 42 are shown as extended in both directions in order to connect up a number of grinding tables and appara tus of the kind described. The fresh raw sand or other material can be supplied at any point in the system. As shown it is supplied either by clam shell bucket 68 or pipes 69 emptying into hoppers 70 in position to discharge into the vessel when elevated.

I The operation of the apparatus illustrated will be readily understood from'the foregoing description. When one of the vessels is in elevated position discharging the abradant and liquid to the grinding table the other vessel is in its lowered position in the pit 11, and receives the abradant and liquid coming back from the grinding table through pipe 8. The material and water as it. enters said vessel is graded according to size either partially or fully, depending upon whether water is admitted into the bot tom of the vessel, into strata arranged at different heights in the vessel, the coarser particles at the bottom, and decreasing in size upwardly. The excess water, scum and other material too line to be used escapes through the overflow spout 40 to the sewer connection 42. During the operation of supplying the abrasive and water from the ele- .vated vessel to the table the abradant is kept in suspension in said vessel by the water supply through the pipe 54, and said pipe also supplies said vessel with water to compensate for the material withdrawn therefrom, so that said vessel remains practically constantly full. As soon as the abradant has been all or, sufliciently dis-.

charged from the elevated vessel, the posi-' tion of the vessels is reversed, either by means of the power cylinders shown in Figs. 1 to 4, or by partly emptying the lowermost vessel to the level of the discharge spout :25, and'allowing the vessels to change positions by the superior weight of the upper vessel which is full of'water (and some abradant) up to the level of the upper discharge spout 40. Prior to changing positions, the spout 12 is moved slightly to one side and after the positions 01" the vessels are changed said spout is moved underneath the outer ends of the discharge pipes of the fresh vessel which has just been lowered, and the operation will continue as before.

With this apparatus no pump or equivalent mechanism for handling the water and sand is required, but the flow is entirely by gravity. The operation also is practically a continuous one since as soon as the abradant from one vessel is exhausted their positions can be reversed so that the freshly charged grading vessel will supply the necessary abradant. The vessels, however, will be so designed that each of them will hold sufficient water and abradant to complete the grinding of one set of glass or other material being ground, so that the reversal of the vessels takes place at the time when the glass on the grinding table is being changed. This desirable in order that the grinding operation may start with the coarsest grade in one of the vessels and be followed gradually by the higher and finer grades therein.

What I claim is:

1. Apparatus for applying abrading material to grinding and smoothing mechanism, comprising in combination, grinding charge to the grinding mechanism.

nism, comprising in combination 2. Apparatus for applying abrading material to grinding and smoothing inechagrniding mechanism, a pair 01 grading vessels, and means arranged to bring said vessels successively into position to receive the abrad ing material and liquid from the grinding mechanism and to discharge to the grinding mechanism, said means being so arranged that when one of said vessels is in position to discharge to the grinding mechanism the other vessel-is in position to receive the abrading material and liquid coming from the grinding mechanism.

3. Apparatus for applying abrading material to grinding and smoothing mechanism, comprising in combination, grinding mechanism, a grading vessel, and mechanism for lowering said vessel to receive the abradi'ng material and liquid coming from the grinding mechanisnr by'gravity flow thereinto and for then elevating said grading vessel to discharge to the grinding mechanism by gravity flow.

l. Apparatus for applying abrading material to, grinding and smoothing mechanism, comprising in combination grinding mechanism, a pair of grading vessels mounted for vertical movement and connected so that when one is elevated the other is lowered, and mechanism for alternatelyreversing the positions of said grading vessels, the one in position to receive the abrading miX ture coming from the grinding mechanism and the other to discharge to the grinding mechanism.

5. Apparatus for applying abrading material to grinding and smoothing mechanism, comprising in combination, grinding mechanism, a pair of grading vessels mounted for up and down movement, a conduit for conducting the abrading mixture from the grinding mechanism, an elevated con- 'duit for conducting the abrading mixture to the grinding mechanism, and mechanism airangedto alternately raise and lower said grading vessels in succession to bring the lowermost one into position to receive the abrading mixture from the first named conduit and the elevated one of said vessels into position to discharge to the elevated conduit.

6. Apparatus for applying abrading ma terial to grinding and smoothing mecha-- nism, Eomprisingin combination, grinding? mechanism, a pair of grading'vessels mounted for up and down. movement, a spout in position to receive the abr-ading mixture emcee from the grinding mechanism and movable to discharge rmost'position, and an eler conducting the abrading iding mechanism and to receiv s i said grading vessels when in elevated po- Sltllln aorading inamechabination, grinding i'ality of movable grading ringed to bring said vessels very into position to receive the mixture coming from the grinding in and iuto position to discharge to the grinding mechanism, and conduits ar- .ranged to catch the overflow from said ves sols when in both positions.

8 Apparatus for applying abrading material to grinding and. smoothing mechanism, comprising ,in combination, grinding mechanism, a pair of grading vessels arranged for up and down movement and connected together so that when onerises the other drops, and conduits arranged to conduct the abrading mixture from the grinding mechanism to the vessel in lowermost position and from the vessel in elevated position to the grinding mechanism, and a water ,supply to the bottoms of both vessels.

9. Apparatus for applying abrading material to grinding and smoothing mechanected together so that when one rises the ply to the bottoms of said vessels, and conduits arranged to'receive the overflow from said vessels in both elevated and lowered p0 sition.

10. Apparatus for terial to grinding and smoothing mechanism, comprising in combination, grinding mechanism, a pair of grading vessels mounted for up and down movement, connections between said vessels so arranged that when one of said' vessels is elevated the other drops, conduits arranged to conduct the abrading mixture from the grinding mechanism to the vessel in lowermost position and from the vessel in elevated position to the grinding mechanism, and a valved outlet from each of said vessels below its upper end, whereby the vessel in lowermost position can be partly emptied to be counterbalanced by'the'vessel in uppermost p955?) tion. 7

11. Apparatus for applying abrading material to grinding and smoothing mechanism, comprising in combination, grinding.

mechanism, a pair of grading vessels mounted for up and down movement, connections between said vessels so arranged that when one of said vessels is lifted the other drops, conduits arranged to conduct the abrading mixture from the grinding mechanism to the vessel in lowermost position'and from the vessel in elevated position to the grinding mechanism, a valved out-let from each of said'vessels below its upper end, whereby the vessel in lowermost position can be partly emptied to be counterbalanced by the vessel in uppermost position, and water sup ply connections to the bottoms of both of said vessels.

12. Apparatus for applying abrading material to grinding and smoothing" mechanism, comprising in combination, grinding mechanism, a pair of grading vessels,-means.

for maintaining the abrading material in suspension in liquid in both of said vessels, and means for conducting the material while in suspension in said liquid alternately from said vessels to said grinding mechanism.

13. Apparatus for applying abrading material to grinding and smoothing mechanism, comprising in combination, grinding mechanism, a pair of grading vessels, means for maintainingthe abrading material in suspension in liquid in both of said vessels, means for conducting the material while in suspension in said liquid alternately from said vessels to said grinding mechanism, and a conduit for receiving the abrading material from the grinding mechanism and conducting the same alternately to said vessels.

14. Apparatus for applying abrading material to grinding and smoothing mechanism, comprising in combination, grinding mechanism, a pair of grading vessels, means for introducing liquid into both of said vessels to maintain the abrading material in suspension therein, and means for conducting the abrading material while in suspension in said liquid alternately from said vessels tothe grinding mechanism.

15. Apparatus for applying abrading material to grinding and smoothing mechanism, comprising in combination, grinding mechanism, a pair of grading vessels, means .fgr introducing liquid into both of said vessels to maintain the abrading material in suspension therein, means 7 for conducting the abradin material while in suspension in said liquid alternately from said vessels to the grinding mechanism, and a conduit for receiving the abrading material from the grinding mechanism and conducting the same alternately to said-vessels;

16. Apparatus for applying abrading maing the same to the grinding mechanism.

17. Apparatus for applying abrading material to grinding and smoothing mechanism, comprising in combination, grinding mechanism, a pair of grading vessels arranged to alternately receive abrading material from the grinding mechanism, means for producing in both of said grading ves sels a downward flow or travel of the material relative to the liquid, and means arranged to withdraw the material and liquid from difi'erent strata in both of said vessels and conduct the .same alternately from said-vessels to the grinding mechanism.

18. Apparatus for applying abrading material to grinding and smoothing mechanism, comprising in combination, grinding mechanism, a pair of grading vessels arranged to alternately receive abrading material from the grinding mechanism, means for producing in both of said vessels an upward flow of liquid, and conduits for withdrawing the material and liquid alternately from said vessels and conducting the same to the grinding mechanism. i v

19. Apparatus for applying abrading material to grinding and smoothing mechanism, comprising in combination, grinding mechanism, a pair of grading vessels arranged to alternately receive abrading matcrial from the grinding mechanism, means for producing in both of said grading vess s an upward flow of liquid, means arged to withdraw the material and liquid 11am difierent strata in said grading vessels, and a. conduit for conducting the material and liquid alternately from said vessels to said grinding mechanism.

In testimony whereof, I have hereunto set my hand.

HALBERT K. HITCHCOOK.

\Vitnesses:

WM. P. LARKIN, WILLIAM B. W'HAnToN.

Gayle! of this patent may be obtained for live cents each, by addressing the Commissioner of Patents. Washington, D. G. 

